Diaphragm



Dec. 18, 1934. F A, STAPLER 1,984,439

DIAPHRAGM Filed Oct. 10, 1923 2 Sheets-Sheet l 5%? gym; A, V ATTORNEY Dec. 18, 1934. F A TAP E 1,984,439

DIAPHRAGM Filed Oct. ,10, 1923 2 Sheets-Sheet 2 4 INVENTOR I]. Ju'w KM BY %WM 3 M A, ATTORNEY Patented Dec. 18, 1934 UNITED STATES PATENT OFFICE DIAPHRAGM Delaware Application October 10, 1928, Serial No. 311,553

7 Claims.

My invention relates to diaphragms, and more particularly to a diaphragm adapted to be used in acoustical sound translating devices.

In accordance with my invention, an article, as aforesaid, is shaped or deformed in response to the successive application of pressure to different faces or sides thereof.

Further in accordance with my invention, a member of sheet material inherently capable of retaining a set formation is brought to diaphragm-constituting configuration by the successive application to opposite faces thereof of pressure-applying members of different geometrical configurations.

Further in accordance with my invention, the last stage pressure-applying member, as aforesaid, comprises die structure for imparting a desired configuration to that surface defining a centrally-disposed diaphragm depression, the imparted configuration preferably comprising a spherical surface and a conical surface extending therefrom or superposed thereon.

My invention also includes the production of a one-piece diaphragm having novel structural features by virtue of which it may be driven or actuated by a member secured thereto only at its mid-point.

For an understanding of my method and for an illustration of one of the forms my novel diaphragm may take reference is to be had to the accompanying drawings in which- Figure 1 is a vertical sectional view, partly in elevation, of die structure for performing the first shaping operation on a blank destined to become a diaphragm.

Figs. 2 through 6 are views similar to Fig. 1 and are illustrative of successive stages of the blank shaping operation.

Fig. 7 is a plan view of a diaphragm constructed in accordance with my invention.

Fig. 8 is a vertical sectional view of the diaphragm shown in Fig. '7.

Fig. 9 is a vertical sectional view, partly in elevation, and is illustrative of an arrangement for securing an actuating member to a diaphragm.

Fig. 10 is a vertical sectional view, partly in elevation, and is illustrative of a modified arrangement for attaching an actuating member to a diaphragm.

Fig. 11 is a vertical sectional view, partly in elevation, of a sound box having associated therewith a diaphragm constructed in accordance with my invention.

In each of the views, the blank or diaphragm is shown as having a thickness much greater than the actual thickness of the material from which the blank or diaphragm is usually constructed. Furthermore, in each of Figs. 2, 3, 4 and 5, the blank is indicated by broken lines in the position assumed thereby at an intermediate stage of the shaping operation.

Referring to Fig. 1, there is illustrated a male die M1 and a female die F1, the latter comprising, in the example shown, separable base and ring sections 1 and 2. The ring section 1 is circular in cross section as is the male die M1.

Confined between the base and ring sections 1 and 2 is a blank or section S of sheet material which usually is generally round and has its peripheral edge clamped between and restrained from movement by the aforesaid base and ring sections 1 and 2.

The lower end of the male die M1, as viewed in 1, comprises a generally cone-shaped surface 3 adapted to be received in a depression or recess 4 in the base member 2 and of similar configuration. Ordinarily, the apexes of the aforesaid surface and depression are somewhat rounded as indicated in Fig. l.

Ordinarily, in accordance with my invention, the blank S is a sheet of metallic material destined to form a diaphragm utilizable for any desired purpose. Particularly, a diaphragm such as herein described may advantageously be comprised in the sound box of a talking machine, phonograph or the like, vibrations being transmitted directly to said diaphragm by a connection leading from the talking machine or phonograph stylus or needle.

The blank S may be formed from any suitable material such, for example, as sheet steel, sheet copper or, and preferably, an aluminum alloy of the type known to the trade as 3-S.O. which is sheet-like and, ordinarily, has a thickness of the order of 0.002 of an inch, more or less.

Material of this character may be readily deformed or shaped is inherently capable of retaining a set formation such as may be imposed, for example, by the herein illustrated die structures.

In the illustrated form of my invention, the plane blank S is initially shaped when the dies M1 and F1 are moved in the proper direction relatively to each other to bring the surface 3 of die M1 closely adjacent the wall of the recess 4. of die F1. As a result of this operation, the blank S, except immediately adjacent its periphery, assumes a shape or configuration corresponding with the wall of the aforesaid wall or recess 4.

The partially shaped blank S is now placed in the die structure illustrated in Fig. 2, in a position the reverse of that illustrated in Fig. 1; that is, the upper surface of the blank S, as illustrated in Fig. 2, is that surface which was lowermost in Fig. l. The dies M2 and F2 of Fig. 2 are identical with the corresponding dies of Fig. l

with the exception that the cone-shaped section.

defined by the surface 312 is somewhat deeper than the similar section 3 shown in Fig. 1. Similarly, the recess or depression 4a, Fig.2 is,

somewhat deeper than the corresponding recess 4, Fig. 1.

As was the case with the die structure illustrated in Fig. 1, proper relative movement of the dies M2 and F2 causes the blank S, interiorly of a region immediately adjacent its periphery, to assume a configuration corresponding with the wall defining the recess 4a.

If; desirable and necessary, the partially shaped blank S may be operated upon again by die structure of the character illustrated in Fig. 3, the latter being identical with the corresponding structure illustrated in Figs. 1 and 2, with the exception that the cone-shaped extension defined by the surface 322 and in which the male die M3 terminates is longer than the corresponding extensions on the male dies of Figs. 1 and 2, while the recess 4b is deeper than the corresponding recesses of Figs. 1 and 2. As shown in the drawings, the partially shaped blank S is placed in the die structure illustrated in Fig. 3 in a position reversed, as aforesaid, from that assumed by the blank in the structure of Fig. 2. Here again, proper relative movement of the male die M3 and female die F3 causes the blank S, in the region thereof interiorly of the ring 11), to assume a configuration corresponding with the wall of recess 41).

The operations described above are performed for the purpose of imparting to the blank S a depression or offset portion of substantially the desired depth. Ordinarily, when manipulating sheet material having the characteristics of material from which diaphragms are formed, it is impracticable to produce a depression of the proper depth by a single shaping operation. Should the latter be attempted, fracture of the blank mightresult since the apex of the male die would probably pierce the blank during the last stage of the operation. In accordance with my invention, however, the desired result is attained by performing the shaping operation in two or more steps and by reversing the blank after each operation, the depth of the depression in the blank depending, in each operation, upon the altitude of the conical extension on the male die utilized for that particular operation. As clearly illustrated in Figs. 1, 2 and 3, the altitudes of the conical extensions for the respective male dies progressively increase in magnitude for the successive operations.

After a depression, usually cone-shaped, has been imparted to the blank S of substantially the desired depthby a suitable number of shaping operations, either three as illustrated on the drawings, or more or less as may be suitable and desirable, the blank is further shaped to impart thereto the desired configuration of the completed diaphragm.

To this end, there may be utilized die structure of the character illustrated in Fig. 4 wherein the operating part of male die M4 most Closely adjacent its stem comprises a section a forming a part of the surface of a sphere, said section a merging into a cone-shaped section b, the apex thereof preferably being rounded as illustrated. The base section 20 of female die F4 comprises a recess 40, the wall defining said recess corresponding with the above described operating part of the male die M4. Accordingly, the wall of said recess 4c comprises a spherical section a1 mating with the corresponding male die section a and a cone-shaped section bl mating with the cone-shaped male die section b, said section b1 being slightly rounded as indicated. The blank S is placed in the die structure comprising the dies M4 and F4 in a position the reverse, as aforesaid, of that assumed by said blank when in the die structure illustrated in Fig. 3 and the dies M4 and F4 are moved relatively in the proper direction to bring the blank S, in the region thereof interiorly of the ring 10, to a shape corresponding with the configuration of the wall or recess 40.

The operation described above in connection with Fig. 4 is performed for the purpose of decreasing the angle between the peripheral plane section of the blank and the shaped section interiorly thereof. This operation also causes the blank to become thinner at the section thereof most closely adjacent its periphery where little stretching has been effected during the preceding deformations. Furthermore, additional depth is thus given to the blank without stretching its center portion. Fig. 4 represents the configuration of the blank before it has been deformed by the dies M4 and F4, while Fig. 5 represents the blank configuration after it has been deformed by said dies. As illustrated in Figs. 5 and 4, the angle yl is smaller than the angle 3;. This feature is desirable in a diaphragm of the character herein described because this change in the angle y causes a more distinct separation of the flexible corrugated edge from the remaining or plunger portion of the diaphragm.

After the completion of the operation described above, the blank is further shaped by die structure .of the character described in Fig. 5 wherein the operating part of the male die M5 comprises a recess a, the wall defining said recess 0 comprising a cone-shaped section if and a section e forming a part of the surface of a sphere, the latter section extending well beyond the recess 0 to form a blank-shaping stem preferably somewhat rounded at its tip. The base section 2d of female die F5 corresponds in configuration with the operating end of the male die M5 and, therefore, comprises a cone-shaped section (21 and a depression defined by a wall 61 forming a part of the surface of a sphere.

After removal of the partially shaped blank S from die structure of the character illustrated in 4, or equivalent, said blank S is placed in the die structure illustrated in Fig. 5 in ,a position the reverse, as aforesaid, of that which it occupied in the shaping step immediately preceding. Accordingly, the blank S is positioned as illustrated by the full lines in Fig. 5, proper relative movement of the cooperating dies causing the blank, interiorly of its periphery, to assume a configuration corresponding with that defined by the walls (11 and e1.

Referring to Fig. 6, there is illustrated die structure for performing the final shaping operation. This structure comprises a male die M6 and a female die F6, the latter comprising a ring section 1e supported by a base section 2e.

The operating part of the male die M6 comprises an outer plane ring-shaped section it disposed at right angles to the axis of the stem of die M6 and from which an edged surface 1' projects. Disposed interiorly of the section h is another ring-shaped section 7', the surface of which is corrugated and, therefore, comprises alternate hills and ridges. Interiorly of the section 7, a ring-shaped recess is is formed by the walls or surfaces Z and m having suitable configurations. Preferably, however, the wall Z is conical while the wall 111. forms a part of the surface of a sphere. Beyond the wall m, there extends a cone-shaped section 11. preferably rounded at its tip, as illustrated.

The base section 2e corresponds in configuration with the above described operating portion of the male die M6. Said base section 2e comprises an outer plane ring-shaped section hl having a ring-shaped channel 21 for the reception of the aforesaid surface 1'. Disposed interiorly of the section hl is another ring-shaped section 7'1 comprising alternate hills and ridges for cooperation with the corrugations of the aforesaid section 9'. Interiorly of the section 7'1, a ring-shaped projection kl is formed by the walls or surfaces Z1 and ml having configurations corresponding, respectively, with the walls Z and m. A recess or depression n1 for cooperation with the aforesaid stem n is formed in part by the wall ml, forming a part of the surface of a sphere, and by a cone-shaped surface into which said Wall ml merges, said cone-shaped surface being rounded at the bottom as illustrated in Fig. 6.

To complete the shaping operation, the partially shaped blank S is placed in die structure of the character illustrated in Fig. 6 in the same relative position that said blank occupied in the die structure illustrated in Fig. 5. That is, in both cases, the same surface of the blank faces the male dies. It will be observed, however, that the portion of the blank that has heretofore been described as being clamped between the ring and base sections of the various female dies is not so arranged in Fig. 6. In this, the last stage operation, this portion of the blank is disposed between the cooperating male and female dies. Proper relative movement of the dies M6 and F6 causes the blank S to conform in configuration with the operating surface of the base section 29 of female die F6, the edged surface 2' cooperating with the channel 11 to cause the blank to be scored whereby a diaphragm of the desired diameter is obtained.

Referring to Figs. 7 and 8, a completed diaphragm D is illustrated and it is a diaphragm of this configuration that is produced by the die structure illustrated in Fig. 6. As shown, diaphragm D comprises a plane section s which was disposed, inwardly of the edged surface 1' and channel 11, between the sections it and b2 of the respective dies M6 and F6. Diaphragm D also comprises a corrugated section s1 formed in the die structure illustrated in Fig. 6 by the cooperating die sections 9' and 7'1. It will be observed that the corrugations thus formed extend tangential to a circle drawn from the center of the diaphragm. inwardly of the aforesaid corrugated section s1, the diaphragm D comprises a conical section s2 sloping from one side of the plane of diaphragm section s and formed by the cooperating sections 1 and 11 of the respective dies M6 and F6. Further toward its center, diaphragm D comprises a spherical section 53 sloping from. the other side of diaphragm section s, said section s3 being formed by the sections 111. and m1 .of the die structure shown in Fig. 6. The central portion of diaphragm D comprises a cone-shaped portion 54 formed by the sections 11 and 111 of the respective dies M6 and F6, said cone-shaped portion 34, preferably, being somewhat rounded as indicated in Fig. 8. It will be noted that the spherical section s3 merges into the conical section s4 and that both these sections extend away from the smaller base of the conical section 32. In other words, the sections s3 and s4 extend in the same direction.

As hereinbefore stated, a diaphragm of the character herein described may advantageously be comprised. in the sound box of a talking machine, phonograph, or the like. When thus utilized, it is particularly desirable that the talking machine or phonograph stylus bar have connection with the diaphragm only at the center of the latter.

A connection of the character just described may be effected in any suitable manner. Thus, for example and as illustrated in Fig. 9, the

diaphragm D may be centrally perforated for the reception of an eyelet 10, the ends of the eyelet being peened upon the inner and outer surfaces of said diaphragm, although, if desirable, a washer 11 of paper, or the like, may be interposed between one peened end of the eyelet 10 and the inner side of the central coneshaped diaphragm section. The stem 12 of a stylus bar 13 is extended within the eyelet and is soldered, or otherwise suitably secured in this position.

In lieu of the above described arrangement for connecting the stylus bar and diaphragm, there may be utilized an arrangement such as illustrated in Fig. 10 wherein the end of the stylus bar stem 12 is placed immediately adjacent or passed through the center of the diaphragm D and is thus secured by a mass of wax 14 which is placed in the position shown while hot and which readily solidifies upon cooling.

In Fig. 9, it will be observed that the stylus bar is arranged on one side of the diaphragm D, while in Fig. 10, the stylus bar is arranged on the opposite side of the diaphragm. Satisfactory results are attained with either arrangement and the particular arrangement utilized, ordinarily, is merely a matter of choice.

Referring to Fig. 11, a diaphragm D, con structed in accordance with my invention, and its cooperating stylus bar are shown as associated with or comprised in the sound box of a talking machine or phonograph. A sound box of the character illustrated comprises a base section 15 having a tubular flanged section 16 within which is disposed a sound-insulating supporting member 17 having a metallic bushing 18 disposed interiorly thereof. The diaphragm D is received at its peripheral edge between the usual washers 19, a cap member 20 coacting with a threaded ring 21 to maintain the washers 19 and diaphragm D in the position illustrated. Ordinarily, cap member 20 is skeleton in form and, therefore, comprises a plurality of passages by virtue of which one side of the diaphragm is placed in direct communication with the surrounding atmospheric medium.

The stylus bar 13 is pivoted at 22 upon a bracket 23 extending laterally from the cap 20, said stylus bar 13 comprising the usual threaded member 24 for retaining a needle or stylus, not

shown, in operative relation with respect thereto.

Associated with the tubular section 16 of the above described sound box is a tone arm or sound-passing conduit, not shown. This conduit confines an elastic medium which is placed in a vibrating condition by impulses imparted thereto by the diaphragm D when the latter is vibrated by the thereto-attached stylus bar 13. As is well understood in the art, the aforesaid tone arm communicates with a radiating horn, not shown.

Different areas or regions of a diaphragm of the character herein illustrated and described move substantially uniformly in response to vibration imposed thereon by the stylus bar, or equivalent, and it is highly desirable to drive or operate such a diaphragm only from its midpoint. However, diaphragm material of the character hereinbefore described is exceedingly thin and mechanically Weak. Therefore, if the stylus 'bar is attached thereto only at one point, in the absence of special measures, an unsatisfactory arrangement is produced.

In accordance with my invention, the diaphragm is so shaped or formed that the stylus bar may be secured thereto only at the diaphragm mid-point. This arrangement has been brought to a practical state because of the particular formation which is imparted to the diaphragm. statically, a cone is the strongest structure under a concentrated load such, for example, as impulses from a stylus bar. A hemisphere is the best structure for a distributed load such, for example, as that imposed by the air on the side of a diaphragm removed from the stylus bar. In accordance with my invention, the diaphragm comprises combined conical and spherical-sections in its central offset region for, as described above, the diaphragm D comprises a spherical section 33 and a superposed conical section 34. At the same time, the diaphragm is otherwise formed, as by the provision of the flexible edge tangential corrugations and circular ridges or channels, to effect the uniform response characteristic as noted above.

Diaphragms constructed in accordance with my invention are not stretched excessively at their centers for, if they were, they would be weakened at the point of attachment to the stylus bar, the point where the greatest strength is necessary. As a rule, the diaphragm material is stretched substantially uniformly although it may be that the part destined to form the flexible edge is stretched to greater extent than are otherparts of the diaphragm. Ordinarily, this is not disadvantageous and may even be desirable.

With some types of material and under certain circumstances, it may be desirable to anneal the material between operations. Thus, it may happen that this operation could advantageously be performed between the two steps illustrated by Figs. 1 and 2. g

It shall be understood that my invention is not to be limited to the precise method described herein and illustrated on the drawings. Thus, for example, the blank S could be produced with a configuration such as imposed by the die structures of Figs. 1, 2 and 3 otherwise than as herein described and otherwise than by a die-shaping operation. Furthermore, I desire it to be understood that my invention is not necessarily limited to a diaphragm of the precise configuration herein illustrated and described, for, while the sections s3 and s4 comprise specific (and preferred) surfaces of revolution, each of which is defined by an equation having a finite number of algebraic terms, namely, a spherical portion for the section 83 and a cone for the section s4, it will be apparent that any other surfaces of revolution which can be defined by equations having a finite number of algebraic terms may be employed in place of the preferred spherical section 33 and the preferred conical section 84, the essential requisite being that one shall particularly withstand a distributed load and the other a concentrated load- In accordance with my invention, the various die-shaping operations are usually so performed that the diameters of the various cone-shaped recesses, or equivalent, are progressively decreased. Thus, the diameter of the coneshaped recess illustrated in Fig. 2 is less than that of the similar recess illustrated in Fig. 1. A similar condition exists with respect to Figs. 3, 4 and 5. Y

I claim as my invention:

1. A diaphragm comprising a member having an offset portion, the surface defining said portion comprising a spherical surface and a conical surface extending therebeyond.

2. A diaphragm comprising a metallic member having a thickness of the order of 0.002 of an inch and'having an ofiset portion, the surface defining said portion comprising a spherical surface and a conical surface extending therebeyond.

3. A diaphragm comprising a circular member having a corrugated section adjacent its periphery, a channel section disposed concentrically within said corrugated section, and a central offset portion, the surface defining said portion comprising surfaces of revolution of dissimilar geometrical figures.

4. The combination with a circular diaphragm having a central offset portion, the surface defining said portion comprising surfaces of revolution of dissimilar geometrical figures both extending in the same direction, of an actuating member secured to said diaphragm only at its mid-point.

5. The combination with a circular diaphragm having a central offset portion, the surface defining said portion comprising a spherical surface and a conical surface extending the-rebeyond, of an actuating member secured to said diaphragm only at the apex of said conical surface.

6. A diaphragm comprising a member having an offset portion, the surface defining said portion comprising in part a sphericalsurface and in part a conical surface. 1

7. A diaphragm comprising a member having an offset portion, the surface defining said portion comprising a spherical surface and a conical surface extending therebeyond said spherical and conical surfaces merging one into the other.

FLORICEL A. STAPLER. 

